Faculty Advisor or Committee Member

Dr. Jonathan Barnett, Advisor

Faculty Advisor or Committee Member

Howard Professor Emeritus, Committee Member

Faculty Advisor or Committee Member

Dr. Nicholas Dembsey, Committee Member

Faculty Advisor or Committee Member

Dr. Brian J. Savilonis, Committee Member

Identifier

etd-052099-131146

Abstract

A fire growth calculation method has been developed that couples a computational fluid dynamics (CFD) model with bench scale cone calorimeter test data for predicting the rate of flame spread on compartment contents such as furniture. The commercial CFD code TASCflow has been applied to solve time averaged conservation equations using an algebraic multigrid solver with mass weighted skewed upstream differencing for advection. Closure models include k-epsilon for turbulence, eddy breakup for combustion following a single step irreversible reaction with Arrhenius rate constant, finite difference radiation transfer, and conjugate heat transfer. Radiation properties are determined from concentrations of soot, CO2 and H2O using the narrow band model of Grosshandler and exponential wide band curve fit model of Modak. The growth in pyrolyzing area is predicted by treating flame spread as a series of piloted ignitions based on coupled gas-fluid boundary conditions. The mass loss rate from a given surface element follows the bench scale test data for input to the combustion prediction. The fire growth model has been tested against foam-fabric mattresses and chairs burned in the furniture calorimeter. In general, agreement between model and experiment for peak heat release rate (HRR), time to peak HRR, and total energy lost is within pm 20%. Used as a proxy for the flame spread velocity, the slope of the HRR curve predicted by model agreed with experiment within pm 20% for all but one case.

Publisher

Worcester Polytechnic Institute

Degree Name

PhD

Department

Fire Protection Engineering

Project Type

Dissertation

Date Accepted

1999-05-20

Accessibility

Unrestricted

Subjects

fire growth, furniture, CFD, Flame spread, Furniture, Fires and fire prevention, Computational fluid dynamics, Cone calorimeters

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